This invention relates to a method for making porous structures and in particular to a method for making microporous structures of a desired shape.
Porous structures are available through a wide variety of processes. However, few processes are capable of producing microporous structures having substantial three-dimensional sizes. One process capable of producing such structures is described in U.S. Pat. No. 4,247,498, which is incorporated herein by reference. Typical processes for making microporous materials, such as classical phase-inversion, are best able to produce structures such as flat sheets. Sintering techniques can produce three-dimensional microporous shapes, but usually such shapes will have a high density and a low void volume.
The process of U.S. Pat. No. 4,247,498, even though it is capable of producing three-dimensional shapes of various sizes, has the drawback that substantial times may be necessary to form such structures due to the slow rate of extraction of the compatible liquid. A need therefore exists for a facile method for making microporous three-dimensional structures of various shapes.